Plastic composition abtb psogess osi kakihg-  sa-w



GEORGE BAKER DUNBAR, OF DETROIT, MICHIGAN.

PLASTIC COMPOSITION AND PIE/GUESS OF MAKING SAME.

1% Drawing.

1 l9 all whom it may concern: Be it known that I, Gnome BAKER DUN- BAR,a citizen of the United States, residing at Detroit, in the county ofWayne and State of Michigan, have invented certain new and usefulImprovements in Plastic: Compositions'und Processes of Making Same, ofwhich the following is a specification.

My invention relates to ii'nprovcrrn-mts in plastic composition andprocess of making same, the composition being particularly designed andadapted for use in molding or pressing into suitable shape various lightweight articles which will not only be fire proof, but adapted to resistthe action of acids,sudden changes in temperature, and the like.

The primary object of the invention is to provide a generally improvedplastic composition particularly adapted for use in the manufacture of alarge variety .of articles which may be readily molded into shape andwhich are exposed to the weather while in use. i

The improved composition is particularly adapted for use as a filling orcovering material for metal parts in protecting the latter from injuryor deterioration by the ac -h,

tion of various deterioratin elements.

By reason of the above my composition is admirably adapted for use inthe manufacture of shell-plugs for temporarily insorting tindsealing theinteriorly threaded ends of lexplosive shells until such time as it isdesi ed to insert the firingcharge therein. My i iproved compositioncomprises the followin ingredients combined in substantially theproportions stated, to wit,-

Resin 60% Carbon (preferably lamp black) Q i 5% Mineral fiber(preferably fas- 'bestos) lalciu-m oxid 10% If desired calcium carbonatemay be sub- ;stit-fltedfor calcium oxid in substantially the proportionstated. y

I desired the proportion of mineral fiber Specification 0! LettersYatent.

Patented July 1.5, 1919.

Application filed January 20, 1919. Serial No. 271,952

may be reduced son'lewhat. for example, say to 20% and the follltwingingredients added in substantially the proportions stated:

Shellac 3% Litharge 2% The litharge may he added to neutralize,

the acids and foreign matter in the com osition, and the shellac,preferably in the orm of gui'nshellac, may be added lo cause thecomposition to shriul; pvrceptihiy while in the molds'aud thus releasethe molded material from the molds In preparing: my improved plasticcomposition the resin is heated and reduced to a liquid state. and whilein such state carhon, preferably in the form of lamp black, is addedthereto and thoroughly moor rated therewith, after which the resultingmaterial is heated to a temperature of from 350 to -l00 Fahrenheit. Atthis stage of the process mineral fiber, preferably asbestos, may beadded and thoroughly incorporated therewith, such asbestos fiber actingas a binding agent in giving strength and fire proof qualities to theresulting article. I then add calcium oxirl or calcium carbonate, whichduring chemical cliange. tllro ws out sufilcient hcat to keep thematerial plastic until I press it into the molds.

If desired, however, shellac and litharge in substantially theproportions stated at the time the asbestos fiber is incorporated, maybe added, but these ingredients are not essential to the resultingcomposition, j It should be understood, however, that I do not limitmyself to the exact quantities of the various ingredients of mycomposition, as above enumerated; as it is obvious that the percentage0? the various ingredients may be varied within reasonable limits tomeet the particular ,,demands or qualities in actual service of I theparticular article desired, without departing from the spirit of myinvention.

Having thus described some of the embodiments of my invention, withouthavin attempted to set forth all the forms in whie it may be made or allthe modes of its use,

what I claim and desire, to secure by Let- .mrsPabent, is,-

1. A plastic-composition, comprising resin, carbon, asbestos, andcalcium oxid.

5 A plastic composition, comprising: (30% resin, 5% carbon, 25% asbestosfiber, and 10% calcium oxid.

' 3. The process of making plastic composition, comprising (1) heatingresin until Jim-chi and heating to reduccd to a liquid state, (2) addingcarbon from 360 to 400 Fahrenheit, (3) mlllin imd thoroughly incol-pointing flwrcwith asbestos fiber, and (4) adding and incorporatingtherein calcium oxid.

In tcstii'nony whcrcof I have affixed my signature.

GEORGE BAKER DUNBAR.

